Nothing in this article affects or limits the powers or duties heretofore conferred by the provisions of chapter sixteen of this code upon the the Secretary of the Department of Health and Human Resources, the Commissioner of the Bureau for Public Health, county health boards, county health officers, municipal health boards, municipal health officers, combined boards of health or any other health agency or political subdivision of this state except insofar as such powers and duties might otherwise apply to the control, reduction or abatement of air pollution. All existing statutes or parts of statutes are, to the extent of their inconsistencies with the provisions of this article and to the extent that they might otherwise apply to the control, reduction or abatement of air pollution, hereby repealed: Provided, That no ordinance previously adopted by any municipality relating to the control, reduction or abatement of air pollution is repealed by this article.